The current plan includes building a three-story “critical care tower” on its property, doubling the size of its emergency room and adding a helipad to the roof. Plans for a cardiac catheterization center and new intensive care ward are also included in the proposal.

Mr. Walter said the town would do all it could to fast-track the hospital’s proposal, which is Riverhead’s largest employer.

“It would be a crime for me and for the town not to push this forward as quickly as possible for the cardiac catheterization component,” he said. “That’s life or death for somebody’s who’s having a heart attack … This project saves lives.”

Mr. Walter said the hospital’s architects and engineers were given “quite the homework assignment” to determine which zoning variances they’d need to have the plan approved.

“He’s got an ambitious site plan and an ambitious approval schedule,” Mr. Walter said. “This is a wonderful thing for the Town of Riverhead.”

While site plans for the project have yet to be submitted, Mr. Mitchell has said he hopes to begin construction in September.